Sound box



Y Dct. 19 1926. M,603,574

R. Y. BARROWS ET M.

SOUND BOX Filed April 50, 1923.

Patented Oct. 19, 1925.

UNITED STATES PATENT oFFlce.

ROBERT Y. BAB/ROWS, OF RUTHERFORD, NEWT JERSEY, AND HAROLD l?. CURTIS, OF NEW YORK, N. Y., ASSIGIQORS TO ROBERT Y. BARROVS, NC., A CORPORATION OF NEW YORK.

SOUND BOX.

Application led April 30,

The invention relates to improvex'nents in sound boxes for talking machines and the like and the main object ot the invention is to provide a sound box which is extremely sensitive and-will more eliiciently and accu rately reproduce the desired sounds. Further and more specific objects, features and advantages will more clearly appear' 'from the detail description given below taken in connection with the accomlianying sheet ot drawings which form a part of this specitication.

ln the drawings, Fig. 1 is a 'face view of a sound box embodying our invention in a preferred term thereof, certain parts being broken away in order to more clearly illustrate the construction. Fig. 2 is a vertical section taken on the line 2 2 ot Fig. 1. Fig. 3 isa horizontal section taken on the line 3 3 of Fig. 1. Fig. 4 is a detail view lillustrating. a modification.

Referring to Figs. 1, 2 and 3, there is shown a sound box having a suitable iframe work l1T suitably recessed to receive a diaphragm 5 with rubber rings 6 and 7 arranged around the periphery ot the dia phragm. In order .to hold the diaphragm and rings 6 and 7 lirmly in operative positionin the sound box there is provided a bezel extending over the face of the dia phragm7 said bezel having a flange 9 engaging the framework in a planeparallel to the plane of the diaphragm and having a circular cylindrical rim 10 extending outwardly and a flange 11 extending inwardly trom the outer edge of said rim in a plane parallel to the plane oft said diaphragm in order to more -fully protect the diaphragm. On the other side the sound box is provided with a suitable tubular member 12 adapted to be connected to the tone arm' of the talking machine -or similar instrument in a manner well understood by those skilled in the art. The bezel 9, 10 and 11 is rigidly secured to the 'frameworks by screws 13. Secured tothe underneath side of the iframework l by screws 14 is a member 15 having screw threaded therein and extending upwardly two conical pointed bearing members 1G and 17. 18 represents a stylus bar provided with conical recesses 19 and 2O against the bottom of which the conical pointed members 16 and 17 respectively bear. The

1921. Serial No. 465,930.

stylus bar is also provided with a conical recess 21 against the bottom of which bears the point of a conical pointed bearing member 22, the bearing member' 22 being resilii ently forced into the conical recess `21 by means of a leaf spring 23 situated in a recess 24- in a 'framework 1. rlhe points ol the conical members 16,17 and 22 and the bottoms of the conical recesses 19, 2() and 21 all lie in a single line forming a pivotal axis about which a stylus bar 18 is adapted to oscillate and said line and pivotal axis also lies in the plane of the diaphragm 5. The stylus bar 1S is curved outwardly at 25 and passes up through a cutaway opening in the rim 1() of the bezel and at its upper end is bent inwardly and rigidly secured to the diaphragm 5 by screw 26. The stylus bar is provided with a needle recess 27 at its lower end into which the usual needle may be secured by screw 28. rllhe spring 23 is slidable in recess 24 laterally, i. e., in a plane at right angles to the plane ot the diaphragm 5 and is likewise free to move over the top ot' the conical Abearing member 22 so that the parts in this respect are made self-adjusting.

It will be seen from the above that there are provided three bearings for pivotally supporting the` stylus bar, said bearings having all their bearing points in arsingle line in the plane of the diaphragm, each of said bearings comprising a conical pointed member engaging the bottom of a conical pointed recess, one of the bearings compris ing a spring pressed member resiliently holding the other bearing members in operative position. By having at least one of the bearings a conical pointed member having its point bearing against the bottom of a cooperative conical recess, lateral movement of the stylus bar in a line at right angles thereto and in the plane of the diaphragm is prevented. Another of .the conical bearing members engaging a cooperative recess prevents rotation ot the stylus bar about the lirst mentioned bearing point in a plane at right angles to the plane in which the stylus bar vibrates. By having the bearing points all in a single line the bearings for the stylus bar are practically frictionless. As the stylus bar operates there is no rubbing ot surfaces anywhere as the only point/s of contact between the stylus bar and its supporting bearing members are three points lying in the pivotal axis' of'the'stylus bar. The stylus bar vsimply rocks about these three points and there is no relative motionV between the conical points ofthe bearing members and the' bottom of the conical recesses. By this arrangement the forces acting' to operate the stylus bar do not have any friction to overcome and also there is no' 'spring in'essure to be overcome by such forces in oscillating the stylus bar and hence the stylus bar is made extremely sensitive and capable of more accurately reproducing the recorded sounds. y'

Referring to F ig. 4, we there show a modiiied arrangement in which the` conical pointed bearing member 1G engagingv the bottom of the conical recess 19 prevents lateral movement of the st ylus har in a line at right angles to the stylus bar in the plane of the diaphragm While the conical bearing member 17 engages the bottom of a V shaped groove 30 in the stylus bar which prevents rotation of the stylus bar in a plane at right angles to the diaphragm and stylus bar and about the point 16 as an axis. The leaf spring Pig-forces a member 31 provided with a knife edge so that it bears down imo a V shaped groove 32 and thereby holds the stylus bar with the recesses 19 and 30 into operative engagement With the conical-i bearing members 16 and 17. In the form shown in this figure as Well as in the form shown in Figs. 1, 2 and 3 all of the recesses have their sides arranged at sutiieientlv great inclination so that the sides of the bearing members-Will not contact therewith during the oscillation of the stylus bar and the conical or knife edge bearing members will engage the recesses onlyat points in the actual line about which the stylus bar is pivoted. In Fig. .ic-the bottom of the conical recess 19 and the bottom of the V-shaped recesses 30 and 32 all lie in a single line in the axis about which the stylus bar 1S is pivoted. The knife edge member 31 is providedwvith a flat top portion 33 adapted to bear against the leaf spring Q3 but free to move laterally thereover. It Will` therefore. appear that it is not necessary that all-of thebearings for the stylus bar be comprised of a conical pointed bearing member engaging the bottom of a conical recess, but it is important that one of the bearings be so arranged in order to take up lateral thrust of the stylus bar.

Also although the invention has been described in great .detail and with respect to preferred forms thereof. it is not desired that the invention be limited to such details and forms since many changes and modifications may be made and the invention embodied in other Widely different forms With'- out departing from the spirit and scope thereof in its broader aspects.

IVe claim- 1. A sound box having a diaphragm, a cooperating stylus bar, and three bearings for pivotally supporting the stylus bar, said bearings-having their bearing points all in a single line, one of said bearings comprising a conical pointed member engaging the bottom of a conical recess and a spring engaging one of said' bearing members for resiliently holding the bearing members in opera-tive position with the bearing points all in the axis about which the stylus bar is adapted to oscillate. said spring beingr slid- Vable in a plane `at right angles to thedirection in which it exerts its spring pressure.

2. A sound box having a diaifihragm, a eooperating stylus bar. and three bearings for pivotally supporting the stylus bar, said bearings having their-bearing points all in a single line, and each of said bearings comprising a conical bearing member, one engaging the bottom of a conical recess and a spring engaging one of said bearing members for resiliently holding the bearing members in operative position with the bearing points all in the axis about Which the stylus bar is adapted to oscillate, said spring being slidable in a plane at right angles'to the di-rection in which it exerts its spring pressure, and slidable Yinthe same plane with respect to the "conical bearing member which it engages.

3. In a sound box having a diaphragm` a cooperating stylus bar, bearing members for ivotally supporting said bar, one of said bearing members being disposed intermediate other bearing members on the opposite side of the bar. and a spring engaging one of said bearing members for resiliently holding said bar between saidbearing members,

said spring being slidable in a plane at rightV angles to the direction in-Which it exerts its spring pressure. f

1.. In a sound boX having a diaphragm, a cooperating stylus bar, bearing members for pivotally supporting said bar, one of said bearing members being disposed intermediatethe bearing members on the opposite side of the bar. and a spring engaging one of said bearing members and an adjacent portion of the sound-boX-for resiliently holding said bar between said bearing members, said spring being slidable both with respect to the sound boX and the engaged bearing member, transversely with Vrespect to the direction in which it'exerts its spring pressure.

5. In a sound box having a diaphragm, a cooperating stylus bar. conical bearing members engaging in conical depressions for pivotally supporting said bar, one vof said bearing members being disposed intermediate the other bearingmembers on the opposite side of the bar, and a spring engaging said intermediate bearing member for resiliently holding the same against said bar, said spring being slidable at right angles to the direction in which it exerts its pressure.

In a sound box having a diaphragm, a cooperating stylus bar, conical bearing members for pivotally supporting said bar, one of said bearing members being disposed intermediate the other bearing members on the opposite side of the bar, and a spring engaging said intermediate bearing member and an adjacent portion ol the sound box 'for resiliently holding said bar against the other bearing members, said spring being slidable both with respect to the sound box and the engaged bearing member transversely of the direction in which it exerts its pressure.

7. In a sound box having a diaphragm and a recess, a cooperating stylus bar, bearing members for pivotally supporting said bar, one of said bearing members being disposed intermediate other bearing members on the opposite side of the bar, and a spring engaging one of said bearing members for resiliently holding said bar between said bearing members, said spring being slidable in the recess of the sound box.

8. In a sound box having a diaphragm and recess, a cooperating stylus bar, bearing members for pivotally supporting said bar, one o'l said bearing members being disposed intermediate the bearing/members on the opposite side of the bar, and a spring engaging one of said bearing members and an adjacentportion of the sound box in the recess therein for resiliently holding said bar between said bearing members, said spring being slidable both with respect to the sound box and the engaged bearing member.

Signed at New York city, in the county of New York, and State of New York, this 27th day of April, A. D. 1921.

ROBERT Y. BARROVVS. HAROLD P. CUR-TIS. 

